Helmut Kogler, Rudolf Scheidl,
"Two Basic Concepts of Hydraulic Switching Converters"
, in M. Linjama and A. Laamanen: Proceedings of the First Workshop on Digital Fluid Power, 3rd October 2008, Tampere, Finland, Seite(n) 113-128, 10-2008, ISBN: 978-952-15-2037-2
Two Basic Concepts of Hydraulic Switching Converters
Sprache des Titels:
Proceedings of the First Workshop on Digital Fluid Power, 3rd October 2008, Tampere, Finland
Hydraulic switching control attempts to transfer concepts from modern electrical drive
control to hydraulics. Both, electrical and hydraulic switching systems can achieve
higher efficiency than resistance control. In this paper, the hydraulic pendants of the
electrical Buck-Converter and Cuk-Converter are introduced. Basically, the hydraulic
switching converters consist of switching elements (fast valves), inductances and
capacities. The active valves are typically switching at a certain frequency in PWMmode.
The Buck-Converter is a traditional step down converter, so the pressure at the
load is always lower than the supply pressure. The concept of the Cuk-Converter even
allows to boost the load pressure up to a higher level than the available supply pressure.
But it is much more difficult to realize the hydraulic switching converters than their
electrical pendants. The wave propagation in the fluid, the impossibility to realize a pure
inductivity and the nonlinearities of the hydraulic elements are major difficulties. This
paper gives an idea of the basic converter concepts and the difficulties concerning the
realization of such drives. Further the results of simulations and measurements are